In 2008 we began to help our students' caretakers, their elderly grandmothers. What began as a handful of guardians has blossomed into a program assisting over 6,200 grannies who are self-organized into 91 groups in three districts.

Impact investing has developed out of traditional philanthropy in an effort to find solutions that allow investors to make profitable investments that can also address social and environmental challenges.

The non-profit Freedom From Hunger is working to help 1.3 million women facing extreme poverty in developing nations work hard towards goals to grow, advance, and develop themselves, their families, and their communities.

One of the interesting things about microfinance in Bangladesh is that its intense market saturation has not resulted in a crisis of over-indebtedness or unmanageable default. "Overlapping" is common -- that is, clients taking loans from several MFIs at the same time.

The microfinance revolution created new ways for the world's poor to secure loans. But microfinance institutions normally don't have the capacity or authority to finance community-level infrastructure projects.

A major problem in Guatemala is the economic disincentive for kids to go to school. Either you can pay for tuition and books from money a family doesn't have, or send your child into the fields to make money for food. Carlos was a rare advocate for an alternative solution.

With a booming social enterprise sector, a number of the world's leading academics, Nobel Prize winners and thinkers, a vibrant private sector, and world-class NGOs like Pratham, India has been dubbed the innovation hub for the West.

Microenterprises on average only employ a few people, but they create job opportunities where very few exist. One individual we supported was Jassim, a young Iraqi entrepreneur who was the sole supporter of his three younger siblings.

Research shows that when girls in the developing world have access to education and are therefore able to earn a living, they move their families, and often their entire communities, out of poverty. This ripple effect is called "The Girl Effect."

Martha Holguin, a 37-year-old microfinance recipient, is standing on her own feet, but she still has a long way to go. "You'll come back to see me as a businesswoman?" she asks. I take a deep breath to hold back my tears.